Fabricated cork sheet



A. S'CHAVOIR FABRICATED CORK SHEET Nov. 23 1926.

Filed April 1924 Patented Nov. 23, 1926.

UNITED. STATES I Peter o ert c151;

ARNOLD L. SCHAVOIR, or STAMFORD, connncricur, assrenon, BY rrnsnnASSIGN- MENTS, TO NEW rnocnss'oonx coMranY, ENG, or nzeoerznrn", newYears, A

CORPORATION on NEW YORK.

FABRIGATED CORK SHEET.

Application filed April 8, 1924. Serial No. 704,953;

My invention relates to a fabricated cork sheet, and more particularlyto an article,

ofthis character consisting mainly of finely granulated cork, so bondedtogether as to form a soft, highly flexible, water proof sheet whichwill not harden or disintegrate as a result of the action of air orwater thereon.

A sheet of material forming the subject matterof my invention has a.roughened or pebbled" surface; is of substantially uniform thicknessthroughout, and may be readily'pro duced by means of machinery wellknown in the rubber working art. In fact, material embodying myinvention is capable of being used in lieu (of various rubber products,and has many advantages thereov'er in that it is notsubject todeterioration, as a result of exposure to light or air; will adhere withgreater tenacity to backingfabric which is preferably used possessesrelatively greater tensile strength can more readily be bonded to othersubstances or materials, and may be much more cheaply produced both asto the value of the ingredients entering thereinto, and in the handlingof the various ingredients during the fahrication of the material.

The main ingredient ofv a sheet embodying any invention is finelygranulated cork which is largely a waste product resulting 'frolnthemanufacture'of other cork products, from Waste-cork bark, and while theproportion of cork entering into the mixture for forming the sheets isbut approximately two parts of said cork to one of other ingredients byweight, in actualloulk the cork-will run fromforty to fifty times thatof theother ingredients.

While the material contains a binder including various gums and oilsincluding some concentrated latex, no heat vulcanizing is required toimpart thedesired characteristics to the material, the curingorsettingof this binder resulting from the mere ex posure of the material toatmospheric air at normal temperatures. It- 'requires no specialtreatment to condition the material for the market, since the product isnot tacky and the volume ,of granulated cork used is sufliciently greatto avoid the presence of any of the other ingredients in the materialexcept in the form of a thin superficial coating upon'each cork granule,each granule also being partially impregnated with these materials sothat they serve i oil, an adhesive known. in the trade as: TechnicalGoulac, a mixture containing animal glue and dextrine; pure rubber knownas smoked sheet, or in lieu thereof, a concen trated latex; anaccelerator such as litharge or super-sulphur (oxidized zinc salt of di-InethyLdi-thio-carba mic acid with or without a clay base) or both, anda suitable coloring material. These ingredients are thoroughly mixed inan ordinary rubber mill and thereafter have mixed therewith insuch amill, a filler of fine granular cork, known as No. 4t or No. 5 cork, ora mixture of these, the size of said granules being such as may beselected by a 14 to a 24tmesh screen.

Byweight, the granular cork. which may be effectively worked into theother ingredients constituting the binder, will be approximately two toone, but in bulk the ratio will be approximately fifty to one, it beingpossible to work a very large volume of the granular cork in a verysmall volume of the binder.

I have found in actual practice that the proportions of the binder foruse with about thirty-three pounds of finely granulated cork should beas follows f 1 pound Vso gumlac (shellac), 4 pounds No. 1 special(rubber substitute), 8 pounds smokedsheet. (or 3 gallons latex), 24ounces litharge, 3 ounces super-sulphur, 1 pound Technical Goulac (glueand dextrine). .To this mixture when I desire ablack finish, I add 12ounces carbon black.

' The composition, after the granular cork has been thoroughly workedinto the other ingredients, is applied to a woven fabric such as cottonduck, by an ordinary calendaring machine, the surface of the duck beforehaving the mixture applied thereto being provided with a coating of gum,glue or rubber cement. V

Vhen applying the mixture or composition by the calendaring machine,suitable pressure is developed so as to not only force the material ofthe binder as well as the cork granules well within the body of thetextile backing, but to materially compress the cork granulesthemselves, larger granules being subjected to a greater degree ofcompression than smaller granules. After leaving the calendaring rolls,the cork granules which have been compressed, will expand, thus givingthe pebbled finish to the composition surface of the sheet. Thecalendaring rolls are run hot, and heat is used only in applying thecomposition to the fabric back.

The various ingredients used in the composition for coating the corkgranules, and the proportions of such as herein described, will permitthe partial hardening of the surfacing composition when exposed to airof a normal temperature, the completed fab-- ric being and remaininghighly flexible, and not being subjected to cracking even when bentsharply.

Owing to the relatively small volume of the binding composition used,the resiliency of the surface finish is practically that of the corkitself, the binder possessing sufiicient elasticity, however, to preventthe separation of the cork granules when the sheet is bent.

The exposed portion of the surface coating then receives a dressing ofshellac which will improve the finish of the product and also facilitateits being cemented to glass or other objects.

The dressing of shellac may be dispensed with if desired, although evenwhen the use of the material does not require it to be cemented to anyobject, the dressing of shellac will improve its appearance although itis not required to enhance the weather proof quality of the product.

The binder used will ensure continued flexibility of the sheet, andexposure to light or air over long periods, will have little or noeffect as to the resiliency of the sheet or its weather proof qualities.

The sheet by reason of the large volume of cork granules, and the thinlayer of the composition containing same ap lied to the textile backing,is very light in weight, per square foot.

In the drawing. a represents the textile backing, b the coating of gum.glue or rubber cement thereon, and 0 the facing of cork filledcomposition.

It is not my intention to limit the inven tion to the precise details ofthe formula for the binding medium herein set forth, it being apparentthat this formula has a large range of variation both as to thequantities of the different ingredients employed, as well as theingredients themselves, although in practice I have found the formulaspecified to give highly satisfactory results.

Having described the invention, what I claim as new and desire to haveprotected sulphur, the quantity of granulated cork being substantiallytwice that of the other ingredients, by weight. I

3. A fabricated cork sheet embodying therein a facing comprising finelygranulated cork, a binder therefor containing rubber, an accelerator, anadhesive, a mixture containing a resin and an oil, and a vegetable gum,the volume of granulated cork being relatively much greater than thevolume of other ingredients, and a surface dressing of shellac.

4. A fabricate-d cork sheet embodying therein a facing comprising finelygranulated cork, a binder therefor containing shellac, a rubbersubstitute including therein resin and rapeseed oil, a mixture of glueand dextrine, pure rubber, litharge and supersulphur, the quantity ofgranulated cork being substantially twice that of the other ingredients,by weight, and a surface dressing of shellac.

5. A fabricated cork sheet including therein a facing comprising a thinstratum of flexible material embodying the following ingredients insubstantially the following proportions33 pounds finely granulated cork,1 pound shellac, 4 pounds of rubber substitute including therein resinand rapeseed oil, 1 pound of a mixture of glue and dextrine. 8 poundssheet, 24 ounces litharge and 3' ounces super-sulphur.

6. A fabricated cork sheet including therein a facing comprising a thinstratum of flexible material embodying the followingingredients insubstantially the. following proportions-33 pounds finely granulatedcork, 1 pound shellac, 4t pounds of rubber substituteincluding thereinresin and rapeseed oil, 1 pound of a mixture of glue and dextrine, 8pounds sheet, 24 ounces litharge granulated cork and a binder thereforcontaining rubber, an accelerator, an adhesive, a mixture containing aresin and an oil, and a vegetable gum, the volume of granulated corkbeing relatively much greater than the "olume of other ingredients.

8. A fabricated cork sheet embodying therein a textile backing havingcemented thereto a facing embodying therein finely granulated cork, abinder therefor containing rubber, an accelerator, an adhesive, amixture containing a resin and an oil, and a vegetable gum, the volumeof granulated cork being relatively much greater than the volume ofother ingredients, and a surface dressing of shellac.

9. A fabricated cork sheet, a textile backing having cemented thereto afacing comprising a thin stratum of flexible material embodying thefollowing ingredients in substantially the following proportions-83pounds finely. granulated cork, 1 pound shellac, 4 pounds of rubbersubstitute including therein resin and rapeseed oil, 1 pound of amixture of glue and dcxtrine, 8 pounds sheet, 24 ounces litharge and 3ounces super-sulphur.

10. A fabricated cork sheet, a textile backing having cemented thereto afacing comprising a thin stratum of flexible material embodying thefollowing ingredients in substantially the following proportions33pounds finely granulated cork, 1 pound shellac, 4 pounds of rubbersubstitute including therein resin and rapeseed oil, 1 pound of amixture of glue and dextrine', 8 pounds sheet, 24: ounces litharge and 8ounces supersulphur, and a surface dressing of shellac.

In Witness whereof I have hereunto affixed my signature this 31st day ofMarch, 1924.

ARNODD L. SOHAVOIR.

